Sources of reduced visual acuity and spectacle treatment options for individuals with Down syndrome: Review of current literature.

Individuals with Down syndrome are known to have a greater prevalence of ocular conditions such as strabismus, nystagmus, elevated refractive error, poor accommodative function, elevated higher-order optical aberrations and corneal abnormalities. Related to these conditions, individuals with Down syndrome commonly have reduced best-corrected visual acuity at both far and near viewing distances across their lifespan. This review summarises the various optical sources of visual acuity reduction in this population and describes clinical trials that have evaluated alternative spectacle prescribing strategies to minimise these optical deficits. Although refractive corrections may still have limitations in their ability to normalise visual acuity for individuals with Down syndrome, the current literature provides evidence for eye care practitioners to consider in their prescribing practices for this population to maximise visual acuity. These considerations include accounting for the presence of elevated higher-order aberrations when determining refractive corrections and considering bifocal lens prescriptions, even for young children with Down syndrome.